Spreading agent



March 26, 1946. P. MEYER 2,397,191

SPREADING AGENT Filed Aug. 25, 1945 Acid aizr lnvenfor: Pcrcg Meger Patented Mar. 26, 1946 SPREADING AGENT Percy Meyer, Ottawa, Ontario, Canada, assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware Application August 23,1943, Serial No. 499,732

- In Great Britain August 4, 1942 .6 Claims.

This invention relates to a new' spreading agent. for oil on water and other surfaces and the method of producing the same. More particularly, it comprises a spreading agent extracted from thermally cracked, including reformed, hydrocarbon petroleum distillates.

The purpose of this invention is to produce in a simple and economical manner a very effective spreading agent for hydrocarbon oils. Another purpose is to produce a material which, when added in small quantities to hydrocarbon oil, will increase its spreading pressure many times when in the form of films. A further purpose of this invention is to produce a new spreading agent for use in mineral oil insecticidal compositions. A still further purpose is to produce a substance effective in breaking crude oil emulsions.

The description of the particular spreading agent of this invention is most clearly given by the process by which it is produced. Generally, this process comprises recovering a certain portion of a sulfuric acid reaction product obtained by treating a cracked gasoline distillate with strong, e. g., 80 %-100%, sulfuric acid as follows: The gasoline distillate is treated with the sulfuric acid. Sludge is settled and separated. The supernatant distillate still containing a small amount of acid-reacting products is then extracted with a small amount of water, and the resulting extract contains the active agent of this invention. This extract may be concentrated, and if desired may be neutralized.

The accompanying drawing discloses diagrammatically a flow sheet of the process for producing the spreading agent of this invention. The limitations on the process will be given with the following detailed description of the drawing.

As may be seen on the drawing, the process comprises four main steps; the first two steps deal with (1) the formation, and (2) the extraction of the spreading agent from the cracked hydrocarbon distillate; while the next two steps deal with (3) the concentration, and (4) the neutralization of the agent after it is extracted.

1. The formation-The spreading agent is formed by treating. a thermally cracked or reformed hydrocarbon gasoline distillate with sulfuric acid in treating unit 1. The distillate continuously enters this unit through line ll into mixer l2 wherein it is mixed with from about 3 to about 5 pounds of concentrated sulfuric acid per barrel of distillate, the acid being introduced through valved line IS. The resulting mixture then passes through line H into settling tank I5.

In settler l5 acid sludge is allowed to settle to the bottom of the tank and is continuously or intermittently withdrawn and discarded through valved line IS. The hydrocarbon distillate containing entrained a small amount of acidic compounds is withdrawn from the top of the tank through line I! to pass to the second step in the process.

2. The emtracti0n.-The entrained acidic compounds are now removed from the distillate in unit 2. To this end the acid-treated distillate from line H entersmixer 2! where it is mixed with a comparatively small amount of water through valved line 22, which amount is between about .5% and 1.5% of the volume of the distillate, and preferably only about 1%. The water need not necessarily be pure, in that ocean water has been found to be very effective for the extraction. The mixture of distillate and water passes through line l3 into extractor-settler 24 wherein an aqueous phase settles out. This phase, which consists mainly of water, acidic compounds, salts and some hydrocarbons, hydrolyzes upon addition of more water, and has the appearance, when fresh, of a blue-colored solution. Therefore, for the purpose of convenience it will hereinafter be called blue-solution. This "blue-solution in itself is a very effective spreading agent, although it is strongly acidic and corrosive. As the blue-solution accumulates in the bottom of settler 24 it may be either continuously or intermittently withdrawn through valved line 25, whereupon it may be used directly as a spreading agent or passed into the third unit of the process for concentration.

The acid-treated extracted distillate is continuously withdrawn from extractor-settler 24 through line 26 for further washing and/or neutralization treatments as may be required in the preparation of a commercial gasoline from thermallycracked or reformed hydrocarbon distillates.

3. The concentration-The blue-solution may be concentrated in either of two different ways, both of which involve hydrolysis, in unit 3 as follows:

(a) A batch of the blue-solution" is passed through valved line 3| into the hydrolyzer 32 wherein it is mixed with about 2-10 times and preferably about 4 times its volume of water, which is introduced into hydrolyzer 32 through valved line 33. This water need not be pure, ordinary ocean water being permissible for such dilution. Water reacts with the "blue-solution to decompose part of it, and upon standing for one or two days, an oily layer oi the concentrated spreading agent or this invention collects on the surface or said water. During this period the added water, which forms the major and lower phase, has become weakly acidic. This weakly acidic water is then drawn oil and discarded through valved line 3'4 at the bottom of hydrolyzer 32 leaving the oily layer 01' concentrated spreading agent hereinafter referred to as the concentrate." This concentrate is then drawn oil through valved line 35 and may be used directly as an eflective spreading agent wherever its acidic promrties are not objectionable. However, due to said acidic properties. it is very corrosive and therefore it is preferable to neutralize it by passing it through the valved line 38 to the fourth unit or the process.

The above is th preferred method of concentrating the blue-solution.

(b) The other way of concentrating the blue solutioncomprises boiling the blue-solution in the hydrolyzer 82 by any suitable heat transfer mechanism such as steam or hot oil coils 37 located in the bottom of said hydrolyzer 32. This boiling also decomposes the "blue-solution and forms a top oily layer which may be removed from the hydrolyzer as described above. Although this heat-concentrated spreading agent has been found to be not quite so effective as the concentrate" produced by dilution in the method above described, nevertheless it has sufficient spreading action to be commercially feasible. This concentrate is also very corrosive and it is preferable to neutralize it in the fourth step of the process.

i. The neutralization.--The corrosive concentrate from hydrolyzer 32 may be neutralized in unit 6 by passing it from valved line it into mixer ti wherein it is mixed with a sumcient amount of a base, of an alkali metal, ammonia, or water=soluble amine, preferably anhydrous ammonia gas, which is introduced through valved line $2 to produce a neutralized eoncentram which has the appearance of a cloudy reddish oil hereinafter referred to as red oil. The amounts or the base required for neutralization are quite small. 1% by weight is required. This cloudy "red oil is fluid above about 40 F. and is not truly miscible in petroleum oil although it produces stable suspensions therein. Its flash point is low due to traces of hydrocarbon distillates, but it is not readily inflammable owing to the water present therein.

The red oil is then passed through line 44 into tank 45 for storage or for blending. For example, a small amount of the raw "blue-solution may be blended with the red oil through valved line 46 to remove its cloudy appearance and produce a clear red oil. The clear red oil may be slightly corrosive, which, however, does not prevent its use for most purposes. of adding a small amount or the "blue-solution other diluents and/or solvents, such as lower alcohols and ketones, which do not react with but are miscible in the red oil," may be added in tank 45 through valved line 41 to clarity or dilute the "red oil" to meet any specific requirements. The final clear diluted and/or blended spreading agent or this invention is withdrawn from the bottom of tank 45 through valved line 48 for packaging and sale.

The advantages of this process are several. It

is simple and economical because, first, the

Instead,

which normally form an undesirable by-product in the conventional acid treatment of cracked distillates: second, the step or extracting with water not only decreases the acid content or the distillate so that less alkali is needed for its neutralization but also removes a major portion of the compounds which frequently cause undesirable emulsions in neutralizing the distillate. Ac-

cordingly, the process or this invention is not only eflective in removing the harmful ingredients from gasoline distillates but also in converting the removed harmful ingredients into a commercially desirable product, namely a superior spreading agent.

Example-The following specific example shows a method of preparation as well as tests or the spreading agent or this invention. First, a continuous stream of cracked and reformed gasoline of Venezuelan origin was acid-treated with about 4 pounds 98% sulfuric acid per barrel of the gasoline. The acid-treated gasoline stream was then mixed with about 1% its volume of ocean water and allowed to settle. The settled phase was then removed and diluted with s times When using anhydrous ammonia about its volume or ocean water and allowed to stand for two days. The oily upper layer formed after this period, 1. e. the concentrate, amounted to about .4% by volume of the gasoline extracted. This concentrate was then divided into two equal parts, only one of which was neutralized with 1% by weight of ammonia gas. Gas oil samples containing difierent concentrations of the neutral-' Ncutralized (In-neutralized Amount of dope, percent by vol. of Area Spreading Area Spreading straight run gas oil covered, pressure covered, pressure sq. cm. (lyrics/cm. sq. cm. (lyrics/cm.

at 21 C. at 21 (3.

28 7 28 24 22 l9 18 19 17 l6 l2 l2 pics are slightly superior in larger amounts.

The spreading agent of this invention may be used efiectively in any one of its forms, "bluesolution," "concentrate or red oil, whichever is most desirable in any particular case. For example, the spreading agent is a very eifective and desirable additive in insecticidal oils used on water in marshy and similar areas to kill mosquitoes and other insects because it does not decrease the toxic efiect of the insecticidal oil. It is also an effective emulsion breaker for crude oil emulsions which occur around oil wells and the like. Although these are only two of the many possible uses or the spreading agent of this invention it can readily be seen from the above table that it can be used advantageously in many other ways.

Amounts of the spreading agent required to cause an oil to spread rapidly over a large area of water or to break emulsions eflectively may vary between about .01 and 5%, amounts between about .1 and 2% usually being quite efiective.

I claim as my invention:

1. A process for producing a spreading agent capable of spreading a hydrocarbon oil on a surface not normally wetted by said oil, comprising (1) treating a. cracked gasoline distillate with between about 3 and 5 pounds of concentrated H2804 per barrel of said distillate to produce an acid sludge, (2) "separating said acid sludge, (3)

extracting the resulting acid distillate with between about ,5% and 1.5% or its volume of water to produce a blue solution, (4) diluting the resuting extract with between about 2 and 10 times its volume of water, (5) allowing the resulting diluted mixture to settle until an oily layer is formed. and (6) separating said oily layer as said spreading agent.

2. The process of claim 1 wherein said water is ocean water.

3. The process of claim 1 wherein the resulting extract is diluted with about 4 times its volume of water. 7

4. A process for producing a spreading agent capable of spreading a hydrocarbon oil on a surface not normally wetted by said oil, comprising (1) treating a cracked gasoline distillate with between about 3 and 5 pounds of concentrated H2804 per barrel of said distillate to produce an acid sludge which is separated, (2) extracting the resulting acid-reacting treated distillate with between about .5% and 1.5% of its volume of water, (3) boiling the resulting extract until an oily layer "is formed, and (4) separating said oily layer as said spreading agent.

5. A spreading agent produced according to the process in claim 1.' 

